# Do everything properly, and componentize
from zope.interface import Interface, implementer

from twisted.application import internet, service, strports
from twisted.internet import defer, endpoints, protocol, reactor
from twisted.protocols import basic
from twisted.python import components
from twisted.spread import pb
from twisted.web import resource, server, static, xmlrpc
from twisted.words.protocols import irc


class IFingerService(Interface):
    def getUser(user):
        """
        Return a deferred returning L{bytes}.
        """

    def getUsers():
        """
        Return a deferred returning a L{list} of L{bytes}.
        """


class IFingerSetterService(Interface):
    def setUser(user, status):
        """
        Set the user's status to something.
        """


def catchError(err):
    return "Internal error in server"


class FingerProtocol(basic.LineReceiver):
    def lineReceived(self, user):
        d = self.factory.getUser(user)
        d.addErrback(catchError)

        def writeValue(value):
            self.transport.write(value + "\r\n")
            self.transport.loseConnection()

        d.addCallback(writeValue)


class IFingerFactory(Interface):
    def getUser(user):
        """
        Return a deferred returning a string.
        """

    def buildProtocol(addr):
        """
        Return a protocol returning a string.
        """


@implementer(IFingerFactory)
class FingerFactoryFromService(protocol.ServerFactory):
    protocol = FingerProtocol

    def __init__(self, service):
        self.service = service

    def getUser(self, user):
        return self.service.getUser(user)


components.registerAdapter(FingerFactoryFromService, IFingerService, IFingerFactory)


class FingerSetterProtocol(basic.LineReceiver):
    def connectionMade(self):
        self.lines = []

    def lineReceived(self, line):
        self.lines.append(line)

    def connectionLost(self, reason):
        if len(self.lines) == 2:
            self.factory.setUser(*self.lines)


class IFingerSetterFactory(Interface):
    def setUser(user, status):
        """
        Return a deferred returning a string.
        """

    def buildProtocol(addr):
        """
        Return a protocol returning a string.
        """


@implementer(IFingerSetterFactory)
class FingerSetterFactoryFromService(protocol.ServerFactory):
    protocol = FingerSetterProtocol

    def __init__(self, service):
        self.service = service

    def setUser(self, user, status):
        self.service.setUser(user, status)


components.registerAdapter(
    FingerSetterFactoryFromService, IFingerSetterService, IFingerSetterFactory
)


class IRCReplyBot(irc.IRCClient):
    def connectionMade(self):
        self.nickname = self.factory.nickname
        irc.IRCClient.connectionMade(self)

    def privmsg(self, user, channel, msg):
        user = user.split("!")[0]
        if self.nickname.lower() == channel.lower():
            d = self.factory.getUser(msg.encode("ascii"))
            d.addErrback(catchError)
            d.addCallback(lambda m: f"Status of {msg}: {m}")
            d.addCallback(lambda m: self.msg(user, m))


class IIRCClientFactory(Interface):

    """
    @ivar nickname
    """

    def getUser(user):
        """
        Return a deferred returning a string.
        """

    def buildProtocol(addr):
        """
        Return a protocol.
        """


@implementer(IIRCClientFactory)
class IRCClientFactoryFromService(protocol.ClientFactory):
    protocol = IRCReplyBot
    nickname = None

    def __init__(self, service):
        self.service = service

    def getUser(self, user):
        return self.service.getUser(user)


components.registerAdapter(
    IRCClientFactoryFromService, IFingerService, IIRCClientFactory
)


class UserStatusTree(resource.Resource):
    def __init__(self, service):
        resource.Resource.__init__(self)
        self.service = service

        # add a specific child for the path "RPC2"
        self.putChild("RPC2", UserStatusXR(self.service))

        # need to do this for resources at the root of the site
        self.putChild("", self)

    def _cb_render_GET(self, users, request):
        userOutput = "".join(
            [f'<li><a href="{user}">{user}</a></li>' for user in users]
        )
        request.write(
            """
            <html><head><title>Users</title></head><body>
            <h1>Users</h1>
            <ul>
            %s
            </ul></body></html>"""
            % userOutput
        )
        request.finish()

    def render_GET(self, request):
        d = self.service.getUsers()
        d.addCallback(self._cb_render_GET, request)

        # signal that the rendering is not complete
        return server.NOT_DONE_YET

    def getChild(self, path, request):
        return UserStatus(user=path, service=self.service)


components.registerAdapter(UserStatusTree, IFingerService, resource.IResource)


class UserStatus(resource.Resource):
    def __init__(self, user, service):
        resource.Resource.__init__(self)
        self.user = user
        self.service = service

    def _cb_render_GET(self, status, request):
        request.write(
            """<html><head><title>%s</title></head>
        <body><h1>%s</h1>
        <p>%s</p>
        </body></html>"""
            % (self.user, self.user, status)
        )
        request.finish()

    def render_GET(self, request):
        d = self.service.getUser(self.user)
        d.addCallback(self._cb_render_GET, request)

        # signal that the rendering is not complete
        return server.NOT_DONE_YET


class UserStatusXR(xmlrpc.XMLRPC):
    def __init__(self, service):
        xmlrpc.XMLRPC.__init__(self)
        self.service = service

    def xmlrpc_getUser(self, user):
        return self.service.getUser(user)

    def xmlrpc_getUsers(self):
        return self.service.getUsers()


class IPerspectiveFinger(Interface):
    def remote_getUser(username):
        """
        Return a user's status.
        """

    def remote_getUsers():
        """
        Return a user's status.
        """


@implementer(IPerspectiveFinger)
class PerspectiveFingerFromService(pb.Root):
    def __init__(self, service):
        self.service = service

    def remote_getUser(self, username):
        return self.service.getUser(username)

    def remote_getUsers(self):
        return self.service.getUsers()


components.registerAdapter(
    PerspectiveFingerFromService, IFingerService, IPerspectiveFinger
)


@implementer(IFingerService)
class FingerService(service.Service):
    def __init__(self, filename):
        self.filename = filename
        self.users = {}

    def _read(self):
        self.users.clear()
        with open(self.filename, "rb") as f:
            for line in f:
                user, status = line.split(b":", 1)
                user = user.strip()
                status = status.strip()
                self.users[user] = status
        self.call = reactor.callLater(30, self._read)

    def getUser(self, user):
        return defer.succeed(self.users.get(user, b"No such user"))

    def getUsers(self):
        return defer.succeed(list(self.users.keys()))

    def startService(self):
        self._read()
        service.Service.startService(self)

    def stopService(self):
        service.Service.stopService(self)
        self.call.cancel()


application = service.Application("finger", uid=1, gid=1)
f = FingerService("/etc/users")
serviceCollection = service.IServiceCollection(application)
f.setServiceParent(serviceCollection)
strports.service("tcp:79", IFingerFactory(f)).setServiceParent(serviceCollection)
strports.service("tcp:8000", server.Site(resource.IResource(f))).setServiceParent(
    serviceCollection
)
i = IIRCClientFactory(f)
i.nickname = "fingerbot"
internet.ClientService(
    endpoints.clientFromString(reactor, "tcp:irc.freenode.org:6667"), i
).setServiceParent(serviceCollection)
strports.service(
    "tcp:8889", pb.PBServerFactory(IPerspectiveFinger(f))
).setServiceParent(serviceCollection)
